I am on Mac OSX Lion, with STS Version: 2.8.1.RELEASE Build Id: 201111221000
The update Groovy-Eclipse M2E integration 2.6.1.xx-20120104-1600-e37 is like chinese food to STS. I install it and an hour later it needs to be installed again. It does not matter how often I install it, and it always installs without error. It just keeps coming back, sort of like Jason in the Friday the 13th movie franchise, but without all the gore.